Yes, unfortunately, some Hollywood plugin APIs clash with OS APIs, not only on Amiga but also on Windows. I really should've used a prefix like "hwp" or something to avoid that, but that's too late now. But there's a workaround in plugin.h without needing you to manipulate it: You can just define the macro HW_PLUGIN_NOPROTOS and the SDK will skip these prototypes, i.e.

Yes, that's a feasible workaround. If you don't want to hack the includes, just place the symbol lookup table in a source file of its own that doesn't include any OS prototypes. Then you should be fine.